Corrigendum: Sizing of Hybrid Energy Storage Systems for Inertial and Primary Frequency Control

In the original article, there was a mistake in Figures 9 and 10, and Tables 1 and 2 as published. There was a mistake in the parameters of the validation model presented in Section 3 Results [available in the reference Alves, E. F. (2021)]. The normalized moment of inertia reported in the article (M = 5.1 s) was wrongly multiplied by 4 in the MATLAB/Simulink model. Due to this error, Figures 9 and 10 reported incorrect dynamics, and Tables 1 and 2 reported incorrect values. The values for parameters (ta - t0) and (tb - ta) in Table 1 were incorrectly reported as 25 s and 15 s, respectively. The correct values are 11 s and 18 s, respectively. The value for parameter Ees1 in Table 2 was incorrectly reported as 101.76 kWh, the correct value is 60 kWh. In addition to Figures 9 and 10, and Tables 1 and 2, corrections have subsequently been made to various reported values throughout the article, namely in Section 3 Results, Sub-sections 3.1 study: a wind-powered offshore platform in the North Sea, 3.2 Sizing of the Energy Storage System, and 3.3 Sizing Validation. The corrected Figures 9 and 10, and Tables 1 and 2 appear below. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.